A method for determining the cumulative coverage rate of surface vessel group search based on three-dimensional coordinate grid

Abstract

The present invention discloses a method for determining the cumulative coverage rate of a surface boat group search based on a three-dimensional coordinate grid, comprising the following steps: 1) constructing a three-dimensional coordinate grid in a mission area; 2) obtaining the motion trajectory of a platform and a search range function of a search device according to the three-dimensional coordinate system; 3) determining whether the grid point is covered by the search by comparing the grid point coordinates in the three-dimensional coordinate system space with the platform and search device model functions; 4) calculating the cumulative coverage rate. The present invention realizes the calculation of the cumulative coverage rate of a continuous search of a surface boat group by constructing a three-dimensional coordinate grid for the mission area and marking the area that has been searched and covered by the grid.

Description

Technical Field

[0001] The invention belongs to a surface vessel group search evaluation technology, in particular to a surface vessel group search cumulative coverage determination method based on a three-dimensional coordinate grid. Background Art

[0002] When a surface vessel group performs air, sea, or underwater search missions, it is often necessary to evaluate the search effect. Therefore, it is necessary to calculate the coverage of the surface vessel group's search in a specific three-dimensional area.

[0003] Traditional coverage calculation methods often use the method of dividing coverage space by task space for calculation. Coverage space and task space are required to be relatively regular for easy calculation. When a surface boat group performs a search mission, the mission area includes irregular underwater terrain, irregular islands or obstacles on the surface, and the mission space is complex. Due to multi-platform, multi-equipment, and multi-stage search, the formation and path of the surface boat group are constantly changing dynamically, and the search space of different platforms and different equipment overlaps. The search capability of the equipment changes with the environment and is difficult to simply accumulate. Therefore, it is difficult to use the traditional coverage calculation method. It is necessary to conduct research on the search coverage of surface boat groups and propose a coverage calculation method that can be used for complex search scenarios of surface boat groups, so as to provide suggestions for evaluating the search effect of surface boat groups and optimizing search plans. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for determining the cumulative coverage rate of a surface vessel group search based on a three-dimensional coordinate grid in view of the defects in the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for determining the cumulative coverage rate of a surface vessel group search based on a three-dimensional coordinate grid, comprising the following steps:

[0006] 1) Construct a three-dimensional coordinate grid in the mission area;

[0007] According to the regional data of the mission area, a three-dimensional coordinate system space with unified coordinates is constructed, and the three-dimensional space is gridded according to the required accuracy and computing power, and the total number of grids is counted;

[0008] 2) According to the three-dimensional coordinate system, obtain the motion trajectory of the platform and the search range function of the search device;

[0009] Suppose the coordinates of platform a at time t are Among them, t is the start time t0 of the task on platform a to the end time t end ; a is the number of the boat group platform;

[0010] The search radius of platform a searching for device b at time t Radar search sector centerline direction Search fan angle

[0011] 3) By comparing the coordinates of the grid points in the three-dimensional coordinate system space with the platform and search device model functions, it is determined whether the grid points are covered by the search;

[0012] From the task start time t0 to the task end time t end , starting with the set increment time △t, for each time point t i , calculate whether the unmarked grid points in the space are within the search range of the platform search device, and mark the grids that have been covered by the search, as follows:

[0013] At time t, the search radius of platform a for device b is The centerline of the radar search sector is oriented The search fan angle is The unmarked grid points are E(x,y,z);

[0014] To determine whether the conditional grid point E(x,y,z) is within the radar search range, the following conditions must be met at the same time:

[0015] 3.1) When c = 0, E(z) ≥ 0; when c = 1, E(z) < 0;

[0016] 3.2) Coordinates of grid point E(x,y,z) and platform a The distance is less than Right now Also:

[0017]

[0018] in, is the coordinate of the grid point E(x,y,z) relative to platform a at time t The position vector of

[0019] 3.3) Vector and the radar heading vector The angle ψ is less than Right now

[0020] Right now:

[0021]

[0022] The search fan angle center line is oriented

[0023]

[0024] Determine whether the grid point E(x, y, z) of the task area at different times is within the search range, take the position coordinates of platform a as the starting point, traverse the surrounding grid points with the grid increment (△x, △y, △z) as the step increment, and combine the search radius As a termination condition;

[0025] The attribute value of the grid point E(x, y, z) within the search range at different times is set to 1, indicating that the grid point is marked as searched and covered;

[0026] 4) Calculate the cumulative coverage;

[0027] After the search task is completed, the number of marked grid points M is counted, and the cumulative coverage μ is:

[0028]

[0029] Where N is the total number of grids constructed by coordinate grid initialization.

[0030] The beneficial effects produced by the present invention are:

[0031] The present invention realizes the calculation of the cumulative coverage rate of the continuous search of the surface boat group by constructing a three-dimensional coordinate grid for the task area and marking the area that has completed the search and coverage by grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0033] Figure 1 is a schematic diagram of a plane search sea area coordinate grid according to an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of a platform device search according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram of platform device search during the time period from t0 to t1 in an embodiment of the present invention;

[0036] Figure 4 It is a flow chart of a method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] like Figure 4 As shown, a method for determining the cumulative coverage rate of a surface vessel group search based on a three-dimensional coordinate grid comprises the following steps:

[0039] (1) Construction of three-dimensional coordinate grid of mission area

[0040] The construction of the three-dimensional coordinate grid of the mission area is mainly based on the geographical data of the mission area, to construct a three-dimensional coordinate system space with unified coordinates, and to grid the three-dimensional space according to the required accuracy and computing power.

[0041] The three-dimensional coordinate system is constructed with the center of the water surface of the three-dimensional mission area as the origin (0,0,0). Based on the data such as the water map of the mission area, the mission area can be abstracted into a three-dimensional coordinate space. Based on the computing power and the required computing accuracy, the three-dimensional space is discretized into grid points E(x,y,z) with (△x,△y,△z) as the grid increment, and the total number of grids is counted, recorded as N.

[0042] Whether the grid point is covered by the search is determined by the attribute value E H (x,y,z) means:

[0043] E H (x, y, z) = 0, indicating that the grid point is not covered by the search;

[0044] E H (x, y, z) = 1, indicating that the grid point is marked as covered by the search.

[0045] Take the search mission in a flat sea area as an example. Figure 1 As shown in the schematic diagram of the plane search sea area coordinate grid, the sea area of ​​4 nautical miles * 4 nautical miles is divided into coordinate grids with increments of △x = 0.25 nautical miles and △y = 0.25 nautical miles, and the total number of grids N = 289;

[0046] At time t0, there are three boats numbered a, b, and c searching in this area. The red grids represent the grids that have been marked and covered by the search. The total number of grids that have been covered by the search at time t0 is M=26.

[0047] (2) Build platform and search device model functions

[0048] The platform and search device model function is constructed based on the motion trajectory of the boat group and the search device parameters, and the motion trajectory of each platform and the time function, and the search range and time function of different search devices on the platform are constructed in turn.

[0049] Take the search for device b at time t as an example. Figure 2 As shown in the schematic diagram of platform device search, it mainly includes the following functions:

[0050] 2.1) The coordinates of platform a at time t Among them, t represents the task start time t0 to the task end time t end ; a represents the number of the boat group platform;

[0051] 2.2) The search radius of platform a searching for device b at time t Radar search sector centerline direction Search fan angle

[0052] in:

[0053] t is the task start time t0 to the task end time t end ;

[0054] a is the number of the boat group platform;

[0055] b is the platform search device number;

[0056] 2.3) Search device attributes c

[0057] c=0, indicating the search equipment on water, which is only valid for grid points E(z)≥0, and E(z)=0 indicates the sea surface;

[0058] c=1, indicating that for underwater search equipment, it is only valid for grid points E(z)<0;

[0059] (3) Coverage area grid marking

[0060] By comparing the grid point coordinates in the three-dimensional coordinate system space with the platform and search device model functions, it is determined whether the grid point is covered by the search.

[0061] From the task start time t0 to the task end time t end , starting with a certain incremental time △t, for each time point t, calculate whether the unmarked grid points E(x, y, z) in the space are within the search range of the platform search device, and mark the grids that have been covered by the search.

[0062] like Figure 2 As shown in the platform device search diagram, the search radius of platform a searching for device b at time t is The centerline of the radar search sector is oriented Search fan angle The grid point E(x,y,z) must satisfy the following conditions within the search range:

[0063] To determine whether the conditional grid point E(x,y,z) is within the radar search range, the following conditions must be met at the same time:

[0064] 1) When c = 0, E(z) ≥ 0; when c = 1, E(z) < 0;

[0065] 2) Coordinates of grid point E(x,y,z) and platform a The distance is less than Right now Right now:

[0066]

[0067] in, is the coordinate of the grid point E(x,y,z) relative to platform a at time t

[0068] The position vector of

[0069]

[0070] 3) Vector and the radar heading vector The angle ψ is less than Right now

[0071] Right now:

[0072]

[0073] The search fan angle center line is oriented

[0074]

[0075] Determine the grid points E(x , y,z) is within the search range, starting from the platform position coordinates, traversing the surrounding grid points with grid increments (△x,△y,△z) as step increments, and combining the search radius It terminates in time as a termination condition to improve the traversal efficiency.

[0076] The attribute value of the grid point E(x,y,z) in the search range at different times is set to 1, indicating that the grid point is marked as searched and covered. Figure 3 As shown in the figure, the cyan line is the search range trajectory line from t0 to t1, and the red marked grids are the grids that have been searched.

[0077] (4) Calculation of cumulative coverage

[0078] After the search task is completed, the number of marked grid points M is counted, and the cumulative coverage μ is:

[0079]

[0080] Where N is the total number of grids constructed by coordinate grid initialization;

[0081] The present invention can select appropriate grid increments according to computing power and required computing accuracy to improve computing efficiency.

[0082] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for determining the cumulative coverage rate of a surface vessel group search based on a three-dimensional coordinate grid, characterized in that: The following steps are involved: 1) Construct a three-dimensional coordinate grid in the mission area; According to the regional data of the mission area, a three-dimensional coordinate system space with unified coordinates is constructed, and the three-dimensional space is gridded according to the required accuracy and computing power, and the total number of grids is counted; 2) According to the three-dimensional coordinate system, the motion trajectory of the platform and the search range function of the search device are obtained; Suppose the coordinates of platform a at time t are Among them, t is the start time t0 of the task on platform a to the end time t end ; a is the number of the boat group platform; The search radius of platform a searching for device b at time t Radar search sector centerline direction Search fan angle 3) By comparing the coordinates of the grid points in the three-dimensional coordinate system space with the platform and search device model functions, it is determined whether the grid points are covered by the search; From the task start time t0 to the task end time t end , starting with the set increment time △t, for each time point t i , calculate whether the unmarked grid points in the space are within the search range of the platform search device, and mark the grids that have been covered by the search, as follows: At time t, the search radius of platform a for device b is The centerline of the radar search sector is oriented The search fan angle is The unmarked grid points are E(x,y,z); To determine whether the grid point E(x,y,z) is within the radar search range, the following conditions must be met at the same time: 3.1) When c = 0, E(z) ≥ 0; when c = 1, E(z) < 0; Wherein, c = 0, which means for water search equipment, it is only valid for grid points E(z) ≥ 0, and E(z) = 0 means the sea surface; c=1, indicating that for underwater search equipment, it is only valid for grid points E(z)<0; 3.2) Coordinates of grid point E(x,y,z) and platform a The distance is less than Right now Also: in, is the coordinate of the grid point E(x,y,z) relative to platform a at time t The position vector of 3.3) Vector and the radar heading vector The angle ψ is less than Right now Right now: The search fan angle centerline is oriented Determine whether the grid point E(x, y, z) of the task area at different times is within the search range, take the position coordinates of platform a as the starting point, traverse the surrounding grid points with the grid increment (△x, △y, △z) as the step increment, and combine the search radius As a termination condition; The attribute value of the grid point E(x, y, z) within the search range at different times is set to 1, indicating that the grid point is marked as searched and covered; 4) Calculate the cumulative coverage; After the search task is completed, the number of marked grid points M is counted, and the cumulative coverage μ is: Where N is the total number of grids constructed by coordinate grid initialization.

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